Can You Keep Harlequin Rasboras With Bettas?

You can keep harlequin rasboras with bettas given you take some precautions and provide the proper tank setup and conditions.

There’s an old idea that bettas should always be kept alone in a tank because they tend to be territorial and aggressive. While this theory is mostly true for most people, it isn’t always true and a few species of fish can share a tank with a betta if you have the right tank conditions.

While you can’t keep bettas together, whether it’s a male and female pair, two males, or two females, you can share tank space with other fish. As long as you choose fish that live in similar water conditions, are the right size, and won’t fight, you can keep them with bettas.

Can You Keep Harlequin Rasboras With Bettas?

One of the most pleasing fish in the community tank is the striking little harlequin rasbora, also called red rasbora, for its coloring. These hardy, schooling fish are usually good for community tanks, but can they live with a betta?

If you decide you would prefer to keep your betta in a tank with other fish, you’ll need to ensure that the tank is large enough. The tank should be 55 gallons at a minimum to allow your betta to “claim” his territory while still allowing enough room for your rasboras room to swim.

Your tank should also include lots of plants (real of fake) and lots of decorations – anything that can serve as a hiding place.

Fish that stick to different zones of the tank are a good idea, as they won’t be fighting your betta for territory. Bettas prefer the surface and mid zones, so peaceful fish that prefer the middle and bottom zones will make excellent tankmates. Rasboras tend to stick near the middle of the tank so this works well.

You can keep harlequin rasboras with your betta, as they fit many of the criteria and, as a bonus, are some of the easiest fish to keep.

I, Lerdsuwa [CC-BY-SA-3.0]

How Many Harlequin Rasboras Can You Have With A Betta?

Harlequin rasbora are schooling fish that like to be kept in small groups of eight-ten fish. This number helps them feel secure, and it’s recommended you keep to this number. Don’t keep harlequin rasboras in isolation.

Having a school of rasboras will also help to spread out any aggression that the betta may exhibit.

The bigger your tank, the better your system will be. Your fish will be happier with more room; the larger a tank is, the easier it is to maintain the correct parameters.

Even in a large community tank with a single betta and a few other fish species, I’d keep my harlequin rasboras to an 8-10 fish school.

Can I Put Rasboras In A Smaller Tank With A Betta?

Smaller tanks are often sold as complete set-ups for beginner fish keepers and are very popular with betta fish. In a 10 gallon tank, bettas should live alone except for maybe a few snails.

It’s a rough guide that you can keep an inch of fish per gallon of water, but you also need to consider how active your fish are and how big they will grow. A shoal of smaller fish will do better in a small tank than a single large fish.

Rasboras grow to about 2″ long and a betta grows to roughly 4″ long. Using the gallon of water per inch rule, you’d only be able to add 3 harlequin rasboras to the tank which is not enough to keep your rasboras healthy.

In addition to stocking issues, in a 10 gallon tank, a betta will claim the entire thing as their territory. If you were to add rasboras to a 10 gallon betta tank, you’d quickly end up with just a betta tank again as the rasboras likely wouldn’t live very long.

What Can Harlequin Rasboras Live With?

Because they are generally peaceful shoaling fish that don’t tend towards fin-nipping or aggressive behavior, harlequin rasboras are some of the most popular fish choices for a community tank.

They have an excellent reputation for being easy to care for and hardy to most diseases. They provide a good focal shoal for your community tank.

You can keep rasboras with a betta fish, provided both have enough space. Other good tankmates for harlequin rasboras include neon tetras, cardinal tetras, Endler’s livebearers, honey gouramis, nocturnal kuhli loaches, and cory catfish.

What Are Good Tankmates For A Betta?

Bettas should never be kept with another betta, even in a large, well-planted tank. Even when female bettas are kept together peacefully, they can turn on each other. It’s no surprise that fish had the name ‘Siamese fighting fish.’

I would also avoid keeping betta with other gouramis like dwarf gouramis and pearl gouramis. Even the peaceful honey gourami may be unsuitable, while better than the other options.

The best tankmates for bettas are invertebrates such as snails and bottom dwellers. Corydoras, kuhli loaches, and plecos are all excellent options.

How To Set Up Tank for Betta and Rasboras

When setting up your betta and rasbora tank, aim to get the biggest tank you can – 55 gallons minimum but even larger is better. Make sure it’s well-planted along the back and sides to give your fish plenty of space to hide and to keep your filter from causing too much water disturbance, as these species prefer stiller water.

You’ll also want to provide rocks, decorations, and possibly driftwood. Each of these will provide hiding places and can help to segment off the tank to allow each species to live in “their” space

Use dark substrate, especially if it’s good for plants, and keep the pH level between 6.0 and 7.5. to keep the acidity of the water optimum for both species.

Check your water parameters and add water softening pillows to your filter if necessary. Avoid using corals in betta aquariums as it makes the pH too high.

Blue Betta fish in front of Plants


Harlequin rasboras make excellent community fish for a tank with a single betta given you’ve got a large enough tank. Rasboras are peaceful shoaling fish who will leave the betta alone. They are not known for fin-nipping or aggressive territorial behavior. However you will need to be weary of the bettas territorial behavior and aggression.

Both species enjoy similar water conditions and are happiest in a tank with plenty of plants, slightly soft water, and plenty of space. A 55-gallon tank with a school of about 8-10 harlequin rasboras, a single betta, and a mystery snail or a few bottom dwellers can be a suitable small community tank.